ICD-10 Code D38.6 – Neoplasm of uncertain behavior of respiratory organ, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D38.6 – Neoplasm of uncertain behavior of respiratory organ, unspecified
What it is
D38.6 identifies a neoplasm in a respiratory organ whose behavior is uncertain, meaning the record does not show whether it is benign or malignant. Use it only when the site is respiratory and the documentation remains nonspecific.
Clinical signs
Clinical features vary; refer to documentation. Findings may include a mass or lesion in a respiratory structure, but the code is based on the pathologic or clinical uncertainty, not on symptoms alone.
When to use this code
Use D38.6 when the provider documents an uncertain-behavior tumor in a respiratory organ and has not classified it as benign or malignant. It may apply after imaging, biopsy, or specialist review when the final behavior is still unclear. If the record names the specific respiratory site, code that site when supported.
Do not use for
Do not use this code for clearly benign or malignant respiratory neoplasms. Do not use it when the documentation identifies a different anatomic site or when the diagnosis is only a suspected mass without confirmation; check documentation.
Coding tip
Verify both the organ site and the “uncertain behavior” wording before assigning D38.6.